Chapter 21

Posing as ordinary visitors, Taro Sakamoto and Shin Asakura slip into the Okutabi Science Museum in search of the concealed lab beneath it. Museum staff talk them into wearing dinosaur costumes for souvenir snapshots, and although Shin brushes off the idea at first, he warms to the picture once it is taken. The pair keep the oversized dinosaur heads on, realizing the masks conveniently obscure their faces.

Shin uses his clairvoyance to pick out a laboratory worker among the crowd, but the man clams up when pressed about reaching the basement. Sakamoto snaps a tooth off a fossil display and uses it to intimidate him, finally coaxing out directions to a secret route tucked inside the annex. Following the steps, the two watch an elevator rise between a pair of mounted bear displays, only for it to refuse them entry. The bears turn out to be machines and lunge at the intruders. Sakamoto and Shin trade blows with the mechanical beast, wreck its systems, and move to shut it down for good so they can get back to Lu before their planned dinner.

Elsewhere in the building, Natsuki Seba and Tanaka deliver Lu to Kashima down on sublevel B2. Kashima immediately notices that the prisoner's hair and gender fail to match the photograph of the clairvoyant boy they were sent to grab, and he warns that deceiving Mr. Reindeer carries a death sentence. Seba admits the capture was a mistake but insists he can still track down the correct target, so Lu and Tanaka are bound and hauled off to another part of the complex. Kashima, set on securing Shin, places his trust in Seba, while Tanaka grumbles about being caged and brands Seba a traitor. Lu, meanwhile, puzzles over the strange marking on Kashima's face, certain she has seen it somewhere before.

Outside, Osaragi and Shishiba climb off a bus, the latter aching from the long ride. Osaragi hands him a chocolate bar she still swears brings good fortune, and the two debate whether the site connects to Slur before heading inside. Back below, once the robotic bear is finally finished, a mechanized dinosaur skeleton roars to life behind Sakamoto, who has never faced a dinosaur and cannot hide his excitement.

This chapter carries the title Let's Go to the Museum!, rendered in Japanese as Hakubutsukan ni Iko!, and belongs to the Lab Arc. It runs nineteen pages and was collected in Volume 3. The installment first appeared in the combined 21/22 issue of 2021 on April 26 of that year. Kashima makes his debut here, while Osaragi and Shishiba receive their first full appearances and Kei Uzuki, known as Slur, is only referenced.